1-2. Don’t be in any rush to become a teacher, my friends. Teaching is highly responsible work. Teachers are held to the strictest standards. And none of us is perfectly qualified. We get it wrong nearly every time we open our mouths. If you could find someone whose speech was perfectly true, you’d have a perfect person, in perfect control of life.
10-12. My friends, this can’t go on. A spring doesn’t gush fresh water one day and brackish the next, does it? Apple trees don’t bear strawberries, do they? Raspberry bushes don’t bear apples, do they? You’re not going to dip into a polluted mud hole and get a cup of clear, cool water, are you?